netlink: Fix for potential NULL-pointer deref

If memory allocation fails, calloc() returns NULL which was not checked
for. The code seems to expect zero array size though, so simply
replacing this call by one of the x*calloc() ones won't work. So guard
the call also by a check for 'len'.

Fixes: db0697ce7f602 ("src: support for flowtable listing")
Signed-off-by: Phil Sutter <phil@nwl.cc>

diff --git a/src/netlink.c b/src/netlink.c
index 51de9c9c8edb2ee7ec7c2a33f314b678de299e26..efae125148b8c3b0f445825f5526c57818d9a765 100644 (file)
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -1790,7 +1790,8 @@ netlink_delinearize_flowtable(struct netlink_ctx *ctx,
        while (dev_array[len])
                len++;
 
-       flowtable->dev_array = calloc(1, len * sizeof(char *));
+       if (len)
+               flowtable->dev_array = xmalloc(len * sizeof(char *));
        for (i = 0; i < len; i++)
                flowtable->dev_array[i] = xstrdup(dev_array[i]);